Comparative reactivity of medicinal gold(I) compounds with the cyclic peptide vasopressin and its diselenide analogue.

The reactions of the medicinal gold(I) compound auranofin and its close analogues with vasopressin and the diselenide analogue were comparatively investigated by LC-electrospray MS/MS. Evidence is gained of the possible cleavage of the S-S and Se-Se bridges induced by Au(I). Notably, we found that, in the absence of reducing agents, the sulfur and selenium atoms are metallated only at high temperature (70 °C) with the preferential binding of gold to selenium. The reaction with the S-S bridge can take place at physiological temperature (37 °C) under reducing conditions. The implications of these results are discussed in the general frame of the reactivity of biologically relevant soft Lewis acids with peptides and proteins.

Altered proTGFα/cleaved TGFα ratios offer new therapeutic strategies in renal carcinoma.

BACKGROUND: Treatment of renal cancer has significantly improved with the arrival to the clinic of kinase inhibitors and immunotherapies. However, the disease is still incurable in advanced stages. The fact that several approved inhibitors for kidney cancer target receptor tyrosine kinases (RTKs) suggests that these proteins play a critical role in the pathophysiology of the disease. Based on these precedents, we decided to explore whether RTKs other than those targeted by approved drugs, contribute to the development of kidney cancer. METHODS: The activation status of 49 RTKs in 44 paired samples of normal and tumor kidney tissue was explored using antibody arrays, with validation by western blotting. Genetic and pharmacologic approaches were followed to study the biological implications of targeting the epidermal growth factor receptor (EGFR) and its ligand Transforming Growth Factor-α (TGFα). RESULTS: Activation of the EGFR was found in a substantial number of tumors. Moreover, kidney tumors expressed elevated levels of TGFα. Down-regulation of EGFR or TGFα using RNAi or their pharmacological targeting with blocking antibodies resulted in inhibition of the proliferation of in vitro cellular models of renal cancer. Importantly, differences in the molecular forms of TGFα expressed by tumors and normal tissues were found. In fact, tumor TGFα was membrane anchored, while that expressed by normal kidney tissue was proteolytically processed. CONCLUSIONS: The EGFR-TGFα axis plays a relevant role in the pathophysiology of kidney cancer. This study unveils a distinctive feature in renal cell carcinomas, which is the presence of membrane-anchored TGFα. That characteristic could be exploited therapeutically to act on tumors expressing transmembrane TGFα, for example, with antibody drug conjugates that could recognize the extracellular region of that protein.

Multisystem inflammatory syndrome in children is driven by zonulin-dependent loss of gut mucosal barrier.

BACKGROUNDWeeks after SARS-CoV-2 infection or exposure, some children develop a severe, life-threatening illness called multisystem inflammatory syndrome in children (MIS-C). Gastrointestinal (GI) symptoms are common in patients with MIS-C, and a severe hyperinflammatory response ensues with potential for cardiac complications. The cause of MIS-C has not been identified to date.METHODSHere, we analyzed biospecimens from 100 children: 19 with MIS-C, 26 with acute COVID-19, and 55 controls. Stools were assessed for SARS-CoV-2 by reverse transcription PCR (RT-PCR), and plasma was examined for markers of breakdown of mucosal barrier integrity, including zonulin. Ultrasensitive antigen detection was used to probe for SARS-CoV-2 antigenemia in plasma, and immune responses were characterized. As a proof of concept, we treated a patient with MIS-C with larazotide, a zonulin antagonist, and monitored the effect on antigenemia and the patient's clinical response.RESULTSWe showed that in children with MIS-C, a prolonged presence of SARS-CoV-2 in the GI tract led to the release of zonulin, a biomarker of intestinal permeability, with subsequent trafficking of SARS-CoV-2 antigens into the bloodstream, leading to hyperinflammation. The patient with MIS-C treated with larazotide had a coinciding decrease in plasma SARS-CoV-2 spike antigen levels and inflammatory markers and a resultant clinical improvement above that achieved with currently available treatments.CONCLUSIONThese mechanistic data on MIS-C pathogenesis provide insight into targets for diagnosing, treating, and preventing MIS-C, which are urgently needed for this increasingly common severe COVID-19-related disease in children.

Sex differences in fear memory consolidation via Tac2 signaling in mice.

Memory formation is key for brain functioning. Uncovering the memory mechanisms is helping us to better understand neural processes in health and disease. Moreover, more specific treatments for fear-related disorders such as posttraumatic stress disorder and phobias may help to decrease their negative impact on mental health. In this line, the Tachykinin 2 (Tac2) pathway in the central amygdala (CeA) has been shown to be sufficient and necessary for the modulation of fear memory consolidation. CeA-Tac2 antagonism and its pharmacogenetic temporal inhibition impair fear memory in male mice. Surprisingly, we demonstrate here the opposite effect of Tac2 blockade on enhancing fear memory consolidation in females. Furthermore, we show that CeA-testosterone in males, CeA-estradiol in females and Akt/GSK3ß/ß-Catenin signaling both mediate the opposite-sex differential Tac2 pathway regulation of fear memory.

Fabry disease-associated globotriaosylceramide induces mechanical allodynia via activation of signaling through proNGF-p75NTR but not mature NGF-TrkA.

Fabry disease (FD) is an X-linked metabolic storage disorder arising from the deficiency of lysosomal α-galactosidase A, which leads to the gradual accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb3), throughout the body. Pain in the extremities is an early symptom of FD; however, the underlying pathophysiological mechanisms remain unknown. α-Galactosidase A knockout animals exhibit nociceptive behaviors, with enhanced expression levels of several ion channels. These characteristics are observed in animals treated with nerve growth factor (NGF). Here, we aimed to elucidate the potential of NGF signaling as a cause of FD-associated pain, using intraplantar Gb3-treated mice displaying mechanical allodynia. Treatment with a neutralizing antibody against a precursor of NGF (proNGF) or its receptor, p75 neurotrophin receptor (p75NTR), resulted in the recovery from Gb3-induced pain. Conversely, anti-NGF and anti-tropomyosin receptor kinase A antibodies failed to exert analgesic effects. Gb3 injection had no effects on the expression levels of proNGF and p75NTR in the plantar skin and dorsal root ganglia, suggesting that Gb3 activates the pain pathway, possibly mediated through functional up-regulation of proNGF-p75NTR signaling. Furthermore, by pharmacological approaches using a protein kinase A (PKA) inhibitor and a cholesterol-removing agent, we found that p75NTR-phosphorylating PKA and lipid rafts for phosphorylated p75NTR translocation were required for Gb3-induced pain. These results suggest that acute exposure to Gb3 induces mechanical allodynia via activation of the proNGF-p75NTR pathway, which involves lipid rafts and PKA. Our findings provide new pathological insights into FD-associated pain, and suggest the need to develop therapeutic interventions targeting proNGF-p75NTR signaling.

BET bromodomain inhibitors regulate keratinocyte plasticity.

Although most acute skin wounds heal rapidly, non-healing skin ulcers represent an increasing and substantial unmet medical need that urgently requires effective therapeutics. Keratinocytes resurface wounds to re-establish the epidermal barrier by transitioning to an activated, migratory state, but this ability is lost in dysfunctional chronic wounds. Small-molecule regulators of keratinocyte plasticity with the potential to reverse keratinocyte malfunction in situ could offer a novel therapeutic approach in skin wound healing. Utilizing high-throughput phenotypic screening of primary keratinocytes, we identify such small molecules, including bromodomain and extra-terminal domain (BET) protein family inhibitors (BETi). BETi induce a sustained activated, migratory state in keratinocytes in vitro, increase activation markers in human epidermis ex vivo and enhance skin wound healing in vivo. Our findings suggest potential clinical utility of BETi in promoting keratinocyte re-epithelialization of skin wounds. Importantly, this novel property of BETi is exclusively observed after transient low-dose exposure, revealing new potential for this compound class.

Neutralizing antibody to proNGF rescues erectile function by regulating the expression of neurotrophic and angiogenic factors in a mouse model of cavernous nerve injury.

BACKGROUND: Radical prostatectomy induces some degree of cavernous nerve injury (CNI) and causes denervation-induced pathologic changes in cavernous vasculature, regardless of the advances in surgical techniques and robotic procedures. The precursor for nerve growth factor (proNGF) is known to be involved in neuronal cell apoptosis and microvascular dysfunction through its receptor p75NTR . OBJECTIVES: To determine the expression of proNGF/p75NTR and the efficacy of proNGF neutralizing antibody (anti-proNGF-Ab) in a mouse model of ED induced by CNI. MATERIALS AND METHODS: Age-matched 12-week-old C57BL/6 mice were distributed into three groups: sham group and bilateral CNI group treated with intracavernous injections of PBS (20 µL) or of anti-proNGF-Ab (20 µg in 20 µL of PBS) on days -3 and 0. Two weeks after treatment, erectile function was measured by electrical stimulation of cavernous nerve. Penis tissues from a separate group of animals were harvested for further analysis. We also determined the efficacy of anti-proNGF-Ab on neural preservation in major pelvic ganglion (MPG) ex vivo. RESULTS: We observed increased penile expression of proNGF and p75NTR after CNI. Intracavernous administration of anti-proNGF-Ab increased nNOS and neurofilament expression probably by enhancing the production of neurotrophic factors, such as neurotrophin-3, NGF, and brain-derived neurotrophic factor. Anti-proNGF-Ab preserved the integrity of cavernous sinusoids, such as pericytes, endothelial cells, and endothelial cell-to-cell junctions, possibly by controlling angiogenic factors (angiopoietin-1, angiopoietin-2, and vascular endothelial growth factor) and induced endogenous eNOS phosphorylation in CNI mice. And finally, treatment with anti-proNGF-Ab rescued erectile function in CNI mice. Anti-proNGF-Ab also enhanced neurite sprouting from MPG exposed to lipopolysaccharide. DISCUSSION AND CONCLUSION: The preservation of damaged cavernous neurovasculature through inhibition of the proNGF/p75NTR pathway may be a novel strategy to treat radical prostatectomy-induced erectile dysfunction.

Antagonism of proNGF or its receptor p75NTR reverses remodelling and improves bladder function in a mouse model of diabetic voiding dysfunction.

AIMS/HYPOTHESIS: Although 80% of diabetic patients will suffer from voiding difficulties and urinary symptoms, defined as diabetic voiding dysfunction (DVD), therapeutic targets and treatment options are limited. We hypothesise that the blockade of the pro-nerve growth factor (NGF)/p75 neurotrophin receptor (p75NTR) axis by an anti-proNGF monoclonal antibody or by a small molecule p75NTR antagonist (THX-B) can restore bladder remodelling (represented by bladder weight) in an animal model of DVD. Secondary outcomes of the study include improvements in bladder compliance, contractility and morphology, as well as in voiding behaviour, proNGF/NGF balance and TNF-α expression. METHODS: In a streptozotocin-induced mouse model of diabetes, diabetic mice received either a blocking anti-proNGF monoclonal antibody or a p75NTR antagonist small molecule as weekly systemic injections for 4 weeks. Animals were tested at baseline (at 2 weeks of diabetes induction), and after 2 and 4 weeks of treatment. Outcomes measured were voiding function with voiding spot assays and cystometry. Bladders were assessed by histological, contractility and protein expression assays. RESULTS: Diabetic mice showed features of DVD as early as 2 weeks after diabetes diagnosis (baseline) presented by hypertrophy, reduced contractility and abnormal cystometric parameters. Following treatment initiation, a twofold increase (p < 0.05) in untreated diabetic mouse bladder weight and thickness compared with non-diabetic controls was observed, and this change was reversed by p75NTR antagonism (37% reduction in bladder weight compared with untreated diabetic mice [95% CI 14%, 60%]) after 4 weeks of treatment. However, blocking proNGF did not help to reverse bladder hypertrophy. While diabetic mice had significantly worse cystometric parameters and contractile responses than non-diabetic controls, proNGF antagonism normalised bladder compliance (0.007 [Q1-Q3; 0.006-0.009] vs 0.015 [Q1-Q3; 0.014-0.029] ml/cmH2O in untreated diabetic mice, representing 62% reduction [95% CI 8%, 110%], p < 0.05) and contractility to KCl, carbachol and electrical field stimulation (p < 0.05 compared with the diabetic group) after 2 weeks of treatment. These effects were not observed after 4 weeks of treatment with proNGF antagonist. p75NTR antagonism did not show important improvements in cystometric parameters after 2 weeks of treatment. Slightly improved bladder compliance (0.01 [Q1-Q3; 0.009-0.012] vs 0.013 [Q1-Q3; 0.011-0.016] ml/cmH2O for untreated diabetic mice) was seen in the p75NTR antagonist-treated group after 4 weeks of treatment with significantly stabilised contractile responses to KCl, carbachol and electric field stimulation (p < 0.05 for each) compared with diabetic mice. Bladder dysfunction observed in diabetic mice was associated with a significant increase in bladder proNGF/NGF ratio (3.1 [±1.2] vs 0.26 [±0.04] ng/pg in control group, p < 0.05 at week 2 of treatment) and TNF-α (p < 0.05). The proNGF/NGF ratio was partially reduced (about 60% reduction) with both treatments (1.03 [±0.6] ng/pg for proNGF antibody-treated group and 1.4 [±0.76] ng/pg for p75NTR blocker-treated group after 2 weeks of treatment), concomitant with a significant decrease in the bladder levels of TNF-α (p < 0.05), despite persistent hyperglycaemia. CONCLUSIONS/INTERPRETATION: Our findings indicate that blockade of proNGF and the p75NTR receptor in diabetes can impede the development and progression of DVD. The reported improvements in morphological and functional features in our DVD model validates the proNGF/p75NTR axis as a potential therapeutic target in this pathology. Graphical abstract.

Targeting zonulin and intestinal epithelial barrier function to prevent onset of arthritis.

Gut microbial dysbiosis is associated with the development of autoimmune disease, but the mechanisms by which microbial dysbiosis affects the transition from asymptomatic autoimmunity to inflammatory disease are incompletely characterized. Here, we identify intestinal barrier integrity as an important checkpoint in translating autoimmunity to inflammation. Zonulin family peptide (zonulin), a potent regulator for intestinal tight junctions, is highly expressed in autoimmune mice and humans and can be used to predict transition from autoimmunity to inflammatory arthritis. Increased serum zonulin levels are accompanied by a leaky intestinal barrier, dysbiosis and inflammation. Restoration of the intestinal barrier in the pre-phase of arthritis using butyrate or a cannabinoid type 1 receptor agonist inhibits the development of arthritis. Moreover, treatment with the zonulin antagonist larazotide acetate, which specifically increases intestinal barrier integrity, effectively reduces arthritis onset. These data identify a preventive approach for the onset of autoimmune disease by specifically targeting impaired intestinal barrier function.

Synthesis, Pharmacological and Structural Characterization of Novel Conopressins from Conus miliaris.

Cone snails produce a fast-acting and often paralyzing venom, largely dominated by disulfide-rich conotoxins targeting ion channels. Although disulfide-poor conopeptides are usually minor components of cone snail venoms, their ability to target key membrane receptors such as GPCRs make them highly valuable as drug lead compounds. From the venom gland transcriptome of Conus miliaris, we report here on the discovery and characterization of two conopressins, which are nonapeptide ligands of the vasopressin/oxytocin receptor family. These novel sequence variants show unusual features, including a charge inversion at the critical position 8, with an aspartate instead of a highly conserved lysine or arginine residue. Both the amidated and acid C-terminal analogues were synthesized, followed by pharmacological characterization on human and zebrafish receptors and structural investigation by NMR. Whereas conopressin-M1 showed weak and only partial agonist activity at hV1bR (amidated form only) and ZFV1a1R (both amidated and acid form), both conopressin-M2 analogues acted as full agonists at the ZFV2 receptor with low micromolar affinity. Together with the NMR structures of amidated conopressins-M1, -M2 and -G, this study provides novel structure-activity relationship information that may help in the design of more selective ligands.

IL-10 inhibits apoptosis in brain tissue around the hematoma after ICH by inhibiting proNGF.

OBJECTIVE: To explore the roles of interleukin-10 (IL-10), proNGF and p75NTR in apoptosis of brain tissues induced by intracerebral hemorrhage (ICH). PATIENTS AND METHODS: According to the time of sample collection after ICH, brain tissue samples were divided into < 6 h group, 6-24 h group (including 24 h), 24-72 h group (including 72 h) and > 72 h group. Meanwhile, 10 tissues that dropped from the beginning at the cortical stoma (distal part of the hematoma) were harvested as controls. AI in brain tissues around the hematoma after ICH was calculated based on TUNEL staining. Expression levels of IL-10, proNGF and p75NTR in brain tissues were determined by quantitative Real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. Protein expressions of Bcl-2 and Bax were detected by Western blot. Rat cortical astrocytes were harvested and cultured in vitro. After transfection of IL-10 overexpression plasmid, expression levels of IL-10, proNGF and p75NTR were detected by Western blot. RESULTS: AI increased in 6-24 h group, 24-72 h group and > 72 h group compared with < 6 h group and control group, which achieved the peak at 24-72 h. However, no significant difference in AI was observed between < 6 h group and control group. With the prolongation of ICH, IL-10 level gradually decreased and achieved the lowest level at 24-72 h. After 72 h, IL-10 level began to increase. Additionally, mRNA and protein levels of proNGF and p75NTR started to upregulate within 6 h of ICH, achieveing the peak at 24-72 h. Bcl-2 level gradually decreased after 6 h of ICH, while Bax level increased. We did not found significant difference in mRNA and protein levels of IL-10 in brain tissues around hematoma between < 6 h group and control group. With the prolongation of ICH, IL-10 level gradually decreased and achieved the lowest level at 24-72 h. After 72 h, IL-10 level began to increase. Transfection with IL-10 overexpression plasmid in rat astrocytes markedly downregulated protein levels of proNGF and p75NTR compared with those of controls. CONCLUSIONS: IL-10 expression is downregulated in brain tissues around the hematoma after ICH. IL-10 alleviates inflammation and apoptosis by inhibiting levels of proNGF, p75NTR and Bax/Bcl-2, thus protecting brain tissue after ICH.

Arginine vasopressin antagonism in heart failure: Current status and possible new directions.

Modulating neurohormonal imbalance is the cornerstone of successful therapy in patients with chronic heart failure with reduced ejection fraction (HFrEF). Plasma arginine vasopressin (AVP) levels are elevated in HFrEF and may contribute to disease progression by excess signaling at either the V1a or V2 receptors. The effects of V1a receptor antagonism are almost completely unexplored, but V1a signaling is closely related to that for angiotensin II and blocking that receptor deserves further study. Interfering with V2 signaling causes free water diuresis and improves congestion without worsening renal function when added to loop diuretics but alone did not improve outcomes when carried into the post-acute phase in one large study. Outcomes in chronic HFrEF are quite good while outcomes in acute HF remain poor. Therefore, further study of V2 or combined V1/V2 blockade of the effects of AVP would most likely yield positive results in patients with acute HF, perhaps especially as alternative, not adjunctive therapy to loop diuretics.

Depilatory chemical thioglycolate affects hair cuticle and cortex, degrades epidermal cornified envelopes and induces proliferation and differentiation responses in keratinocytes.

Thioglycolate is a potent depilatory agent. In addition, it has been proposed to be useful as a penetration enhancer for transepidermal drug delivery. However, the effects on hair structure and stress responses it elicits in epidermal keratinocytes have not been fully characterised. We have used label-free confocal and fluorescence lifetime imaging supported by electron microscopy to demonstrate how thioglycolate damages hair cuticle cells by generating breakages along the endocuticle and leading to swelling of cortex cells. Maleimide staining of free SH-groups and a decrease in the average fluorescence lifetime of endogenous fluorophores demonstrate a specific change in protein structure in both hair cuticle and cortex. We found that the thioglycolate damages cornified envelopes isolated from the stratum corneum of the epidermis. However, thioglycolate-treated epidermal equivalent cultures recover within 48 hours, which highlights the reversibility of the damage. HaCaT keratinocytes respond to thioglycolate by increased proliferation, onset of differentiation and expression of the chaperone protein Hsp 70, but not Hsp 27. Up-regulation of involucrin can be blocked by an application of c-Jun N-terminal kinase (JNK) inhibitor, but the up-regulation of Hsp 70 takes place regardless of the presence of the JNK inhibitor.

[The pathway of vasopressin as a pharmacological target in nephrology: a narrative review].

ADH is a hormone secreted by neurohypophysis that plays different roles based on the target organ. At the renal level, this peptide is capable of causing electrolyte-free water absorption, thus playing a key role in the hydro-electrolytic balance. There are pathologies and disorders that jeopardize this balance and, in this field, ADH receptor inhibitors such as Vaptans could play a key role. By inhibiting the activation pathway of vasopressin, they are potentially useful in euvolemic and hypervolemic hypotonic hyponatremia. However, clinical trials in heart failure have not given favourable results on clinical outcomes. Even in SIADH, despite their wide use, there is no agreement by experts on their use. Since vaptans inhibit the cAMP pathway in tubular cells, their use has been proposed to inhibit cystogenesis. A clinical trial has shown favourable effects on ADPKD progression. Because vaptans have been shown to be effective in models of renal cysts disorders other than ADPKD, their use has been proposed in diseases such as nephronophthisis and recessive autosomal polycystic disease. Other possible uses of vaptans could be in kidney transplantation and cardiorenal syndrome. Due to the activity of ADH in coagulation and haemostasis, ADH's activation pathway by Desmopressin Acetate could be a useful strategy to reduce the risk of bleeding in biopsies in patients with haemorrhagic risk.

Vasopressin and alcohol: a multifaceted relationship.

BACKGROUND: Arginine vasopressin (VP) has been implicated in a number of neuropsychiatric disorders with an emphasis on situations where stress increased the severity of the disorder. Based on this hypothesized role for VP in neuropsychiatric disorders, much research is currently being undertaken in humans and animals to test VP as a target for treatment of a number of these disorders including alcohol abuse. OBJECTIVES: To provide a summary of the literature regarding the role of VP in alcohol- and stress-related behaviors including the use of drugs that target VP in clinical trials. RESULTS: Changes in various components of the VP system occur with alcohol and stress. Manipulating VP or its receptors can alter alcohol- and stress-related behaviors including tolerance to alcohol, alcohol drinking, and anxiety-like behavior. Finally, the hypothalamic-pituitary-adrenal axis response to alcohol is also altered by manipulating the VP system. However, clinical trials of VP antagonists have had mixed results. CONCLUSIONS: A review of VP's involvement in alcohol's actions demonstrates that there is much to be learned about brain regions involved in VP-mediated effects on behavior. Thus, future work should focus on elucidating relevant brain regions. By using previous knowledge of the actions of VP and determining the brain regions and/or systems involved in its different behavioral effects, it may be possible to identify a specific receptor subtype target, drug treatment combination, or specific clinical contexts that may point toward a more successful treatment.

Inhibition of the precursor and mature forms of HIV-1 protease as a tool for drug evaluation.

HIV-1 protease (PR) is a homodimeric enzyme that is autocatalytically cleaved from the Gag-Pol precursor. Known PR inhibitors bind the mature enzyme several orders of magnitude more strongly than the PR precursor. Inhibition of PR at the precursor level, however, may stop the process at its rate-limiting step before the proteolytic cascade is initiated. Due to its structural heterogeneity, limited solubility and autoprocessing, the PR precursor is difficult to access by classical methods, and limited knowledge regarding precursor inhibition is available. Here, we describe a cell-based assay addressing precursor inhibition. We used a reporter molecule containing the transframe (TFP) and p6* peptides, PR, and N-terminal fragment of reverse transcriptase flanked by the fluorescent proteins mCherry and EGFP on its N- and C- termini, respectively. The level of FRET between EGFP and mCherry indicates the amount of unprocessed reporter, allowing specific monitoring of precursor inhibition. The inhibition can be quantified by flow cytometry. Additionally, two microscopy techniques confirmed that the reporter remains unprocessed within individual cells upon inhibition. We tested darunavir, atazanavir and nelfinavir and their combinations against wild-type PR. Shedding light on an inhibitor's ability to act on non-mature forms of PR may aid novel strategies for next-generation drug design.

The Neuropeptide Tac2 Controls a Distributed Brain State Induced by Chronic Social Isolation Stress.

Chronic social isolation causes severe psychological effects in humans, but their neural bases remain poorly understood. 2 weeks (but not 24 hr) of social isolation stress (SIS) caused multiple behavioral changes in mice and induced brain-wide upregulation of the neuropeptide tachykinin 2 (Tac2)/neurokinin B (NkB). Systemic administration of an Nk3R antagonist prevented virtually all of the behavioral effects of chronic SIS. Conversely, enhancing NkB expression and release phenocopied SIS in group-housed mice, promoting aggression and converting stimulus-locked defensive behaviors to persistent responses. Multiplexed analysis of Tac2/NkB function in multiple brain areas revealed dissociable, region-specific requirements for both the peptide and its receptor in different SIS-induced behavioral changes. Thus, Tac2 coordinates a pleiotropic brain state caused by SIS via a distributed mode of action. These data reveal the profound effects of prolonged social isolation on brain chemistry and function and suggest potential new therapeutic applications for Nk3R antagonists.

A clue to unprecedented strategy to HIV eradication: "Lock-in and apoptosis".

Despite the development of antiretroviral therapy against HIV, eradication of the virus from the body, as a means to a cure, remains in progress. A "kick and kill" strategy proposes "kick" of the latent HIV to an active HIV to eventually be "killed". Latency-reverting agents that can perform the "kick" function are under development and have shown promise. Management of the infected cells not to produce virions after the "kick" step is important to this strategy. Here we show that a newly synthesized compound, L-HIPPO, captures the HIV-1 protein Pr55Gag and intercepts its function to translocate the virus from the cytoplasm to the plasma membrane leading to virion budding. The infecting virus thus "locked-in" subsequently induces apoptosis of the host cells. This "lock-in and apoptosis" approach performed by our novel compound in HIV-infected cells provides a means to bridge the gap between the "kick" and "kill" steps of this eradication strategy. By building upon previous progress in latency reverting agents, our compound appears to provide a promising step toward the goal of HIV eradication from the body.

Combined Catalase and ADH Inhibition Ameliorates Ethanol-Induced Myocardial Dysfunction Despite Causing Oxidative Stress in Conscious Female Rats.

BACKGROUND: Ethanol (EtOH)-evoked oxidative stress, which contributes to myocardial dysfunction in proestrus rats, is mediated by increases in NADPH oxidase (Nox) activity, malondialdehyde (MDA), and ERK1/2 phosphorylation. Whether these biochemical responses, which are triggered by alcohol-derived acetaldehyde in noncardiac tissues, occur in proestrus rats' hearts remains unknown. Therefore, we elucidated the roles of alcohol dehydrogenase (ADH), cytochrome P4502E1 (CYP2E1), and catalase, which catalyze alcohol oxidation to acetaldehyde, in these alcohol-evoked biochemical and hemodynamic responses in proestrus rats. METHODS: Conscious proestrus rats prepared for measurements of left ventricular (LV) function and blood pressure (BP) received EtOH (1.5 g/kg, intravenous [i.v.] infusion over 30 minutes) or saline 30 minutes after an ADH and CYP2E1 inhibitor, 4-methylpyrazole (4-MP) (82 mg/kg, intraperitoneal), a catalase inhibitor, 3-AT (0.5 g/kg, i.v.), their combination, or vehicle. LV function and BP were monitored for additional 60 minutes after EtOH or saline infusion before collecting the hearts for ex vivo measurements of LV reactive oxygen species (ROS), Nox activity, MDA, and ERK1/2 phosphorylation. RESULTS: EtOH reduced LV function (dP/dtmax and LV developed pressure) and BP, and increased cardiac Nox activity, ROS and MDA levels, and ERK1/2 phosphorylation. Either inhibitor partially, and their combination significantly, attenuated these responses despite the substantially higher blood EtOH level, and the increased cardiac oxidative stress and reduced BP caused by 3-AT alone or with 4-MP. The inhibitors reduced cardiac MDA level and reversed EtOH effect on cardiac and plasma MDA. CONCLUSIONS: EtOH oxidative metabolism plays a pivotal role in the EtOH-evoked LV oxidative stress and dysfunction in proestrus rats. Notably, catalase inhibition (3-AT) caused cardiac oxidative stress and hypotension.